Nervous System General Interest Facts

The nervous system is a cellular network that monitors the internal and external environments of an organism. The nervous system has two parts: the central nervous system and peripheral nervous system.

The brain is part of the central nervous system. Image by Flickr.com, courtesy of Martin Pettitt

Central Nervous System

The brain and spinal cord make up the central nervous system. This is the largest part of the nervous system. The adult brain weighs about three pounds.

Peripheral Nervous System

The peripheral nervous system consists of nerves, which are bundles of neurons. Your peripheral nervous system helps connect your central nervous system to the rest of your body.

Nervous Tissue

Neurons and glial cells are the two primary cell types in nervous tissue. Neurons convey nerve messages. Neurons are surrounded by glial cells, which help protect them.

Input

Input to the nervous system is recognized by our senses: smell, vision, taste and hearing. Organisms also recognize pain, pressure and temperature, which are referred to as the somatic senses.

Fun Fact

Your body has around 30,000 million nerve cells, which can each transmit 1,000 nerve impulses per second. The number of nerve cells in the human brain is larger than the number of stars in the Milky Way galaxy.

References

• Bryn Mawr: Fun Facts
• Estrella Mountain Community College: The Nervous System
• University of Washington: Neuroscience for Kids